DESCRIPTION

Parse::CPAN::Meta provides three methods: load_file, load_json_string, and load_yaml_string. These will read and deserialize CPAN metafiles, and are described below in detail.

Parse::CPAN::Meta provides a legacy API of only two functions, based on the YAML functions of the same name. Wherever possible, identical calling semantics are used. These may only be used with YAML sources.

All error reporting is done with exceptions (die'ing).

Note that META files are expected to be in UTF-8 encoding, only. When converted string data, it must first be decoded from UTF-8.

METHODS

load_file

This method will read the named file and deserialize it to a data structure, determining whether it should be JSON or YAML based on the filename. On Perl 5.8.1 or later, the file will be read using the ":utf8" IO layer.

load_yaml_string

This method deserializes the given string of YAML and returns the first document in it. (CPAN metadata files should always have only one document.) If the source was UTF-8 encoded, the string must be decoded before calling load_yaml_string.

load_json_string

This method deserializes the given string of JSON and the result. If the source was UTF-8 encoded, the string must be decoded before calling load_json_string.

yaml_backend

my $backend = Parse::CPAN::Meta->yaml_backend;

Returns the module name of the YAML serializer. See "ENVIRONMENT" for details.

json_backend

my $backend = Parse::CPAN::Meta->json_backend;

Returns the module name of the JSON serializer. This will either be JSON::PP or JSON. Even if PERL_JSON_BACKEND is set, this will return JSON as further delegation is handled by the JSON module. See "ENVIRONMENT" for details.

FUNCTIONS

For maintenance clarity, no functions are exported. These functions are available for backwards compatibility only and are best avoided in favor of load_file.

Load

my @yaml = Parse::CPAN::Meta::Load( $string );

Parses a string containing a valid YAML stream into a list of Perl data structures.

LoadFile

my @yaml = Parse::CPAN::Meta::LoadFile( 'META.yml' );

Reads the YAML stream from a file instead of a string.

ENVIRONMENT

PERL_JSON_BACKEND

By default, JSON::PP will be used for deserializing JSON data. If the PERL_JSON_BACKEND environment variable exists, is true and is not "JSON::PP", then the JSON module (version 2.5 or greater) will be loaded and used to interpret PERL_JSON_BACKEND. If JSON is not installed or is too old, an exception will be thrown.

PERL_YAML_BACKEND

By default, CPAN::Meta::YAML will be used for deserializing YAML data. If the PERL_YAML_BACKEND environment variable is defined, then it is interpreted as a module to use for deserialization. The given module must be installed, must load correctly and must implement the Load() function or an exception will be thrown.